1) This invention is electro-mechanical. It involves electrical feedback of a mechanical device and falls under the CPC section H. It attaches to a sewer back-flow preventer valve, otherwise known as a backwater valve, made by others.
2) Due to an intense storm causing flooding in our area, we experienced a municipal sewer back-flow into the basement of our primary residence as well as an equal back-flow of sewer water into the basements of the homes of our near living families. In the aftermath of this event, and the subsequent insurance claims and rebuilding, the insurer insisted that sewer back-flow prevention be installed in our homes so that our policy could be continued.
3) During our preparations for the installation of our sewer back-flow preventer valve, otherwise known as a backwater valve, the contractor made it clear that an installed sewer back-flow preventer valve comes with some challenges. The first challenge was the need for the periodical cleaning of the valve to ensure proper functioning of the valve. If the valve were to become filled with debris, the valve could fail to close properly and fully during an event of a municipal sewer back-flow, allowing flooding which the valve was supposed to prevent.
4) The question arose, how would one know if the valve was becoming impaired with dirt and in need of cleaning. A regular regimen of cleaning would prove useful but will not compensate for variance in usage. Also, neglect is a consequence of a busy lifestyle.
5) The second concern was in regard to the valve operating properly during an event of municipal sewer back-flow. If an event were to occur that resulted in the sewer back-flow valve successfully closing, then municipal sewer contents would be prevented from flooding the basement. However, a closed sewer back-flow preventer valve would also prevent the egress of wastewater generated by the occupants within the dwelling. This would result in secondary flooding, as wastewater would back up into the basement through the floor drain or a downstairs shower drain or even a toilet.
6) The contractor was queried on these issues but was unable to offer an alarm for the closure of the valve, nor had they any idea concerning a device that could warn the homeowner of a dirt impaired valve.
7) An internet search was started for a device that could be attached to the sewer back-flow preventer valve to offer some sort of warning. Feedback from the contractor indicated that other homeowners who also had a valve installed were concerned with these issues as well. Some individuals had gone as far as home fashioned devices that could warn of a closed valve.
8) As I was unable to locate a device that provided a comprehensive solution, I set about to design my own. It was a challenge because I did not want to do anything to the back-flow preventer valve,—which was supplied by the contractor in advance—such that they would refuse to install it. I also did not want to do anything to the valve that might cause the plumbing inspector to disapprove of the installation of the sewer back-flow preventer. Thus, the design was made as unobtrusive as possible and constructed to be obviously harmless to the main purpose of the sewer back-flow preventer valve. The installation was successful. The plumbers felt the attached device was satisfactory and the installation also passed city inspection.
9) The prototype installed at my principle residence was designed and constructed within a narrow timeframe due to constraints placed upon us by the insurance company and the contractor. However, it was my intention to build a device that could also be installed upon a preexisting valve in order to satisfy strong retail demand for such a device. The prototype used the simplest methods of construction in order to fit our allotted time. The final designs could either be part of the backwater valve when manufactured by the backwater valve OEM or be an ‘off the shelf’, installed by homeowners with some technical ability.
10) In my initial search for a device that would offer some type of alert, I found one device online that offered some protection. It was sold by an online distributor at http://www.backwater-valves.com/flood-alarm.asp. This device works by sensing continuity between two electrical probes and I considered this device, however it has its drawbacks. The metal probes will corrode and/or be coated with residue and is hence unreliable. It does not inform residents as to whether a backwater valve has actually closed, but merely alarms if municipal sewer water is backing up, if it is in fact in working order at all. Neither does it offer any alert as to the buildup of debris in the valve. I searched for an associated patent for this device and found “Sewer alarm apparatus having a probe”, U.S. Pat. No. 10,032,357, application Ser. No. 15/137,599. This design focuses on “detecting the presence of liquid within a pipe” Cite 7, and may not be associated with the device at the website mentioned, although its function appears identical. This idea does not achieve the needed result and is subject to corrosion and failure.
11) Once my search for a patented device began, I decided to file a provisional patent application No. 62/761,423 for my Sewer Back-flow Preventer Monitor. I continued my search for devices and found “Sewer alarm” U.S. Pat. No. 4,922,234, application Ser. No. 07/275,371. This device contains a “buoyant mercury switch tethered” Cite 4, to sense high water level. As an electrician working in the manufacturing industry for almost 40 years, I know this to be a poor application. Sewage is constantly moving through this valve. This switch will fail quickly and also it can impair the function of the valve. It will get coated with sewage and block the flow. Also, it offers no alert of the valve's sediment buildup.
12) Another patent I observed is “Sewer backup alarm” U.S. Pat. No. 9,123,230, application Ser. No. 13/894,153. This alarm “includes a float device and a wireless alert device” Cite 5. Again, experience shows that this float switch will become coated with sewage and fail. Also, it offers no alert for debris buildup in the valve.
13) I looked at “Sewer line backup detection, alarm and detention apparatus” U.S. Pat. No. 4,546,346, application Ser. No. 06/475,688. This device, a “pneumatic switch is actuated by a flexible diaphragm” Cite 3. is also poor construct. These switches a notorious for failure, more so in this environment. This switch will get plugged up in short order and the diaphragm will decay. The final patent I discovered which bore similarities to what I intended to build is covered under pending application U.S. Ser. No. 15/720,925 and is an “apparatus for detecting an impending sewer backup by detecting fluid undulations of predetermined magnitude” Cite 1, the focus of this device is predictive. This device is a non-starter, as it is designed for a valve which municipalities have been steering away from. The reason being the flapper of this valve rests on the bottom of the valve housing and will glue to the bottom in the sediment, hence it will not close and a flood ensues. This design uses a “tilt switch carried by the gate” Cite 2, which can only demonstrate a single position of the flapper, and as such, cannot offer a user an alarm when the valve needs cleaning. Nor can it offer an alarm if the switch is being used for ‘predictive purposes’, as outlined in the application. This wireless switch would be positioned on the inside of the valve, in the sediment. It is not practical, as the battery will have to be replaced and there will not be the will to dismantle the valve, clean the switch from the nasty stuff, and change the battery. This application also postulates the possible use of “a sensor for sensing fluid undulations of predetermined magnitude” Cite 8, without detailing what type of sensor it is. However, based on the requirements described, it would be a costly sensor, multiples of the price of the valve itself. It is therefore not cost effective.
12) I searched for a patent that utilized reed switches or a magnetometer and a magnet to indicate valve position. I found only “Valve position indicator” Cite 6, U.S. Pat. No. 3,896,280A, an apparently expired patent. My prototype utilizes a similar device as this, but within the context of a sewer backwater valve instead of an automotive valve, much in the same way the aforementioned patents utilized existing hardware within the context of their patents. For example, a pressure switch or a float switch, or a continuity switch, all devices that have previously been patented.